The present invention relates broadly to the field of telephony and the use of modems and computers. More specifically, the present invention relates to a method and apparatus for informing a computer modem user of the presence of an inbound telephone call, and allowing the user to place the modem connection on hold, receive the call, and either preserve or sever the modem connection.
With the proliferation of Internet Service Providers (ISP), increased modem capacity and the growing popularity of global computer networks, many people spend considerable amounts of time at their computers connected to their respective ISP via a modem. In order to preserve the modem connection, the popular telephone feature of call waiting must be disabled, or data transfer over the modem will be disturbed. However, some modems are able to recover from the interruption of call waiting, and may restore any lost data by sending an interrupt to the other modem. Thus, the call waiting signal is unnoticeable to the computer user. As a result, the computer user is unreachable by telephone while connected to the ISP unless a second telephone line is provided. Many existing homes have only one telephone line, and the cost of installing a second telephone line and paying an additional monthly service fee make the second telephone line an undesirable solution.
Another popular telephone feature is caller ID, where the telephone number and possibly the name of the caller is displayed to a user before the user accepts the incoming call. A device that could utilize the features of call waiting and caller ID to allow a user to identify callers while simultaneously using a computer modem on the same telephone line would prove very convenient and useful.
U.S. Pat. No. 4,995,074 to Goldman et al. discloses a system for interrupting a data session between computers connected over a telephone line to allow the handling of an incoming call and restoring the connection between computers once the incoming call is terminated. The Goldman patent teaches a system wherein an interface must be physically located at both the host computer site and the terminal user site.
The present invention teaches a method and apparatus for interrupting computers connected over a telephone line to allow the handling of an incoming telephone call and restoring the connection between computers after the incoming call is terminated, but is far simpler than the system disclosed in the Goldman patent. In the present invention, there is no need for hardware or software to be physically located at both the host site and terminal site; the present invention teaches a system located only at the terminal site. Thus, the present invention does not limit a user to computers employing a matching interface, and allows the user to receive incoming calls while connected to any host computer. Because the present invention does not require the host computer to use any special hardware or software, fewer components are required than in the system disclosed in the Goldman patent, making the present invention less expensive to produce and install.
The present invention solves the problems described above by providing a method and apparatus to inform an online computer user of the presence of an incoming telephone call without disturbing the modem connection. The present invention comprises a telephony device connected to a telephone line, modem and telephone, and utilizes a call waiting service provided by the telephone company. Call waiting indicates the presence of an incoming call by providing a tone defined as two tone bursts separated by approximately 9.7 seconds of silence, each burst having a duration of approximately 300 milliseconds and a frequency of approximately 440 hz. Upon detection of a call waiting tone the device generates a four second warbling tone to a piezoelectric sounding device or energizes a ringer, thus alerting the user to the presence of the inbound telephone call. The user may answer or ignore the telephone call. Caller identifiers included in incoming calls may be used to alert the user of the origin of the incoming call before the user decides to accept or ignore the call.
When the device determines that the user has lifted the telephone set, it places the modem on hold, waits 700 ms to generate a hook flash signal, then connects the telephone to the telephone line, thus establishing a connection to the caller. When the user terminates the call by replacing the telephone set, the device may generate another hook flash signal and reconnect the modem to the Internet Service Provider. If the user picks up and hangs up quickly (within 5-7 seconds depending on baud rate, modem and service provider) the modem may be able to reestablish the previous connection without having to redial the ISP.
In one aspect, the present invention provides a method of interfacing an online computer user, a modem, and incoming telephone calls by detecting the presence of an incoming telephone call, notifying the computer user of the incoming call, placing the modem on hold, connecting the computer user with the incoming telephone call, and restoring the modem connection when the user terminates the incoming telephone call. Caller identification may also be performed, thus providing a filtering mechanism for the user. The user may be alerted to the identification of every incoming call, or only designated callers. The user may be alerted by a light emitting diode (LED), audible signal, or a voice delivered over a speaker.
In another aspect, the present invention provides a telephony device for interfacing an online computer user, modem and incoming telephone calls. The telephony device attached to a modem, telephone set, and telephone line utilizing the feature of call waiting. The telephony device comprises a connection for a telephone line, a connection for a telephone set and a connection for a modem. It further includes a switch for switching the telephone set and the modem to the telephone line, a processor for detecting the presence of call waiting signals and controllably operating the switch, and a signal generator for alerting the user of the presence of an incoming telephone call. The alerting signal may be a lighted display, audible sound or ringer, or a synthesized voice. The device may also incorporate a caller identification display to alert the user of the origin of every incoming call, or only alert the user to incoming calls from designated callers. Certain telephone numbers may be programmed into the device so that special treatment and priority can be given to those designated callers.
Other features and advantages of the present invention will become apparent from the following detailed description of the invention when it is considered in conjunction with the accompanying drawings.